It is known that energy farming and production using renewable resources is becoming increasingly important as the costs of nonrenewable fuels such as fossil fuels continue to rise, and earth's nonrenewable resources are depleted more and more each day. It can also be appreciated that harvesting wind energy in residential and rural settings for powering energy needs for such activities that occur in residential and rural settings are beneficial in addition to commercial scale wind farms that harvest, develop and produce electricity. Although large-scale wind turbines work well for harvesting electricity on commercial and industrial scales, these wind turbines are not amenable to use in more of a residential and rural setting. Therefore, there is a need to provide an improved wind turbine and blade assembly that scales effectively to a wide variety of different sizes, and is affordable, reliable, simple and cost-effective and thereby amenable for use in residential and rural settings to harvest wind energy capable of meeting utility needs for such settings.
It can also be appreciated that a wind turbine and blade assembly that is fully scalable would be advantageous for producing wind turbines with multiple wattage outputs.
Therefore, it is another feature of the present invention to provide a wind turbine and blade assembly being fully scalable to have different wattage outputs.
Because of the heat generated, especially in wind turbines that use gearing systems to operate at multiple speeds, and the combination of usage and environmental factors that can lead to system failure, whether by excessive winds, intense ambient heat or other elements, and the wear on the blades and experienced by moving parts within the wind turbine, the service life of the wind turbine may be unduly shortened, with increased deployment costs particularly as the turbines servicing requirements increase or the useful life of the turbine is shortened.
Therefore, there is a need to provide an improved wind turbine and blade assembly that is more easily serviceable in part by requiring fewer parts that require service, and by locating more of the serviceable parts and components of the wind turbine near the tower used to support the wind turbine and blade assembly.
Residential and rural wind turbines and blade assemblies usually have blades which are smaller than those used in commercial or industrial production of electricity using commercial or industrial scale turbines. Many of these turbines, including smaller scale wind turbines, require large amounts of wind energy to start the rotation of the blade assembly by breaking the cogging torque generated by a magnetic flux density within the wind turbine assembly.
Therefore, there is a need to provide a wind turbine and blade assembly wherein the cogging torque is reduced thereby reducing the stresses on the wind turbine and blade assembly and increasing the rotational startup for smaller and medium wattage wind turbines.
It is also well known that the blade assembly is an integral component to a wind turbine. More specifically, the less wind energy necessary for rotating the blade assembly translates into an increased efficiency of the wind turbine or the capability of the wind turbine to harvest more wind energy at lower wind velocities.
Therefore, there is a need to provide a blade assembly being contoured to increase the efficiency of the blade assembly by extracting more energy from less wind, and to extract more energy from a smaller rotational diameter.
In addition to the desire to increase blade efficiency, it is well known in the art of wind turbines that the blade assembly can experience catastrophic forces from excessive or high-velocity winds, thereby causing failure of the blade assembly and wind turbine.
Therefore, in systems with either small or large blade diameters, there is a need to provide a blade assembly that is designed to mitigate and/or prevent the damage that may result to the blade assembly and wind turbine from excessive or high-velocity winds by configuring the blade assembly such that the blades are rotated out of the wind, and by the wind, relative to the magnitude of force exerted on the blade by the wind.
Present wind turbines rely on wind diagnostics and analysis hardware or systems to assess the velocity and other factors relating to the approaching and passing wind. The hardware and systems are in communication with blade pitch controls to pitch or tune the blades depending on the velocity or other factors associated with the approaching and passing wind. The blades are then turned into the wind to the desired blade pitch/angle to control the velocity or RPM of blade rotation. This type of turbine design unnecessarily requires the added expense of wind diagnostics and analysis hardware or systems to assess the wind and then provide correction to the angle of the blades. These current apparatuses and methods that use added electromechanical control systems for blade rotation require an increased parts count with increased service requirements and multiple points of failure. And, there is increased latency in an electromechanical approach which makes it less responsive to wind bursts and rapid changes in wind velocity.
Because direct drive turbines do not have the braking characteristics of gear-based systems, it is known that braking systems are an important element of direct drive turbine designs. The process of turning the blades in the instant invention provides an alternative or enhancement to mechanical braking systems.
Therefore, a need has been identified in the art to provide an improved wind turbine and blade assembly where the blade assembly includes built-in means to automatically and simultaneously tune or control the angle of the blades relative to and by the wind force acting on the blades by controlled resistance of the blades out of the wind.
In light of the foregoing, there is a need in the art for an improved wind turbine and blade assembly for direct drive (gearless) wind turbines having the previously described features and advantages.
Thus, the primary feature or advantage of the present invention is an improved wind turbine and blade assembly for direct drive (gearless) wind turbines.
One or more of these and/or other features or advantages of the present invention will become apparent from the specification and claims that follow.